Proof of tobacco claims?

Question

We all know that tobacco forms a habit and can potentially end your life but, how have these following claims been proven?

Tobacco can stunt growth? *

Only 1 ciggarette can cause lung cancer?

*Is this claiming smoking 1/2 a pack a day could stunt growth not a pack every few months?

Have questions like that been proven and do you think they are true

Answer 1

No it can't stunt growth.

Its possibly that one cig can cause lung cancer (highly Doubtful), BUT there would be other factors.. i.e. Someone who is working around hazadous chemicals all there life, has one cig and gets lung cancer.

Not sure about the third Q

I think what I said is true